Dev improvements to pgweb

Folks,

First, lemme thank the web team for doing a terrific job of making it
really easy to build a pgweb test server.  I suspect that the web team
may have cause to regret, in the future, making it easy enough that I
can do it.

Before I submit a patch covering all of the following, I'd like to make
sure that none of the below things are intentional:

1. dev build instructions don't mention the HTML validator script

2. pyyaml is required to follow the dev build instructions, but is not
in requirements.txt (is this because it's *only* required for dev builds?)

3.  The dev instructions don't mention setting the database *user* or
password in settings_local (probably assuming that the webserver owner
and the db user are the same).

4. the HTML validator script has no ability to recurse or follow links;
it only validates one page at a time.

For the last item, I was thinking of writing a script which wraps the
current HTML validator script, but either has the ability to take a set
of URLs from a list file, or to load all files in the templates/pages
tree below the target directory.

-- 
Josh Berkus
PostgreSQL Experts Inc.
http://pgexperts.com